66 reptiles. 



2. Alligator. 



Jaws oblong, very depressed, broad, nearly parallel, rounded in 

 front. Forehead with a small longitudinal ridge between the or- 

 bits. Teeth unequal, the lower canines received into a pit in the 

 edge of the upper jaw. Nuchal and cervical plates separate. Feet 

 fringed behind. Toes half-webbed, the outer front toe free. Nos- 

 trils separated by a bony septum arising from the upper edge. N. 

 America. The muzzle elongates by age. 



The Alligator. Alligator Missisipensis, Gray, Syn. 62. Cro- 

 codilus Missisipensis, Daud. Rept. ii. 412. C. Cuvieri, Leach, 

 Zool. Misc. ii. 102, t. C. Lucius, Cuv. Ann. Mus. x. §• Oss. 



Fos. v. t. 1,/. 8, t. 2, /. 4. Tiedem. Amph. 58, t. 4. Merrem, 34. 

 Dum. et Bib. E. G. iii. 75, t. 25, 26. The Alligator, Catesby, Ca- 

 rol, t. 63. 



In the young it is as long from the eyes to the nostrils, as the 

 width of the muzzle at the 9th tooth, in the old specimens the dis- 

 tance is half as long again. 



a. Stuffed. Length 38 inches. N. America. From Dr. Man- 



tell's collection. 



b. Stuffed. Length 45 inches. N. America. Presented by E. 



Doubleday, Esq. 



c. Stuffed. Length 35 inches. N. America. 



d. e. Very young, in spirits. N. America. From Dr. Mantell's 



collection. 

 /. Adult, stuffed. Length 84 inches. N. America. 

 g. Half grown, stuffed. Length 63 inches. N. America. 



A. Cuvieri, Leach, Zool. Misc. (the specimen figured). 

 A. Half grown. Length 66 inches. N. America. 

 i. Skeleton of young. N.America. From Dr. Mantell's collection. 



3. Caiman. 



Jaws oblong, depressed, subpyramidical, rounded and swol- 

 len at the end, without any frontal ridges or maxillary pits. 

 Forehead flat, smooth. Teeth ^ , unequal, lower canine teeth fit- 

 ting into a pit in the inner edge of the upper jaw. Eyebrows de- 

 fended with 3 bony plates. Toes scarcely webbed. Nuchal aud 

 cervical plates united into one group ? Trop. America. 



The Trigonal Cayman. Caiman trigonatus. Crocodilus t. 

 Schn. Amph. 161. Seba, Thes. i. t. 105,/. 3. Tiedem. Amph. t. 7. 

 Wagler, Syst. 140. Natterer, Ann. Mus. Vien. i. 323, t. 26. Shaw, 

 Zool. i. 58. Crocodilus palpebrosus, var. 2, Cuv. Ann. Mus. x. Sf 

 Oss. Foss. v. t. 2,/. 1. Gray, Syn. 63. Dum. et Bib. E. G. iii. 72. 



One row of nuchal plates, which are separated from the cervi- 

 cal plates by a line of slender pointed scales ; head triangular, ob- 



